convert xml filled dataset to a datatable/base

ok i have a dataset I filled from a xml file, populated a datagrid with it (mostly to see if the data was really there), ok i got that much but I am very new to XML, so what i want to do is fill a database with the new data from the xml file. I have really not gotten any further theni started a week ago, to much coffee.
any help would be great, or suggestions links to code sample, all i have found was how to turn dataset into xml, but not the other way around I did search this forum but didnt find anything helpful to me.

thanks in advance.